Lifetime’s latest thriller drops viewers into the action right from the jump. Under desaturated grey/blue skies, introverted lawyer Mel (Lindsey Desbach) rides a ferry to Feng Key island. She’s headed to the titular party island not for a vacation, though; she’s there to identify the body of her drowned younger sister, Georgia (Andrea Prevatt).

It’s immediately clear that something unusual is afoot when Mel visits the police station and unhelpful Detective Alex Hurley dismisses her suspicions. Georgia’s body was found on the beach with her wallet, but her phone and passport are missing. Later, as Mel begins to investigate, frightened local Kaya (Mia Rose) insists that Georgia was wearing a bathing suit when she was pulled from the water, so where was she keeping her wallet?

Clearly something is amiss and seemingly everyone knows it, including Wayward hostel owner Keaton (Adam Harper) and his manager Paula (Kate Dailey). The pair act friendly to Mel, but in a very facile, surface-level way. As Mel pokes around, she learns that local dive bar owner Jever (James Bobo) has an illegal side hustle, and Kaya insinuates that Georgia isn’t the first girl to disappear: their friend Faye (Mackenzie Thompson) is also gone and missing posters frequent bulletin boards wherever Mel goes.

The first act of Danger on Party Island is the film’s best because of where it might go. Writer Hannah Maryse Robinson’s screenplay wisely never pretends something bizarre isn’t going on, which allows the narrative to focus on who is involved and what are they covering up.

While the film wastes no time establishing its premise, Danger on Party Island does struggle to sustain its mystery. This is, in part, because it has no interest in developing its characters outside of their relationship to Georgia’s death. None of the characters are provided any depth or development; they’re all either informants, suspects, and/or red herrings.

Sadly this lack of characterization includes Mel, who is defined first and foremost by her dogged tenacity. There are a few moments that interrogate how her grief and the investigation are affecting her job, but the timeline of the film is only a few days, so outside of a pair of phone calls, Mel is in private investigator mode 24/7.

Thankfully Desbach has the personality to carry the film. Mel’s refusal to back down – despite being attacked, chased through the woods, and repeatedly told to leave the island – is always presented as an admirable trait. The audience may not know much about her, but Mel is dogged and smart.

This is never more apparent than a second act development that questions whether Georgia is even dead or simply taking a “digital detox” that has prevented her from reaching out. Mel and her mother Alice (Annie Cook) watch the social media post together and both women immediately identify it as little more than a lie and a distraction. It’s a plot development that confirms that Mel is smart and savvy; it’s not simply a twist to complicate the narrative.

Unfortunately the truth about what is happening on the island is exactly what viewers will expect. As a result, the reveal renders the climax slightly underwhelming and bogs down the pacing of the last act. Direct Danny J Boyle attempts to keep the energy up with a frenetic series of double crosses and chase sequences, but these are hampered by the obvious budgetary constraints.

Not helping matters is the film’s overall lack of geography: whereas the hostel has a gorgeous, spa-like aesthetic with exposed wood beams and a lounging pool below the entrance, Feng Key island never comes together visually. It’s unclear what the proximity of one location is to another and the “tombstoning” cliffs that Georgia purportedly perished over are never even seen.

Then there’s the question of how many people are on the island. While there are a few crowd shots, the island is often conveniently empty, which belies the film’s titular “party” scene. Hell, at one point Mel runs into Jever’s bar to avoid being followed, only to discover the drinking establishment completely empty!

These issues, paired with the underwhelming third act, undermine the film’s strong set-up. Danger on Party Island is a reasonably entertaining diversion, but a more sensational reveal and better character work would have helped to make it more memorable. Instead it’s another middle of the road Lifetime entry.

Danger on Party Island airs Wednesday, March 20 (8pm EST) on Lifetime.